19979655 has 16 divisors (see below), whose sum is σ = 32999424. Its totient is φ = 10311840.

The previous prime is 19979647. The next prime is 19979657. The reversal of 19979655 is 55697991.

It is a happy number.

It is not a de Polignac number, because 19979655 - 2³ = 19979647 is a prime.

It is a super-2 number, since 2×19979655² = 798373227838050, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19979598 and 19979607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19979657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21019 + ... + 21948.

It is an arithmetic number, because the mean of its divisors is an integer number (2062464).

Almost surely, 2^19979655 is an apocalyptic number.

19979655 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

19979655 is a deficient number, since it is larger than the sum of its proper divisors (13019769).

19979655 is a wasteful number, since it uses less digits than its factorization.

19979655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43006.

The product of its digits is 765450, while the sum is 51.

The square root of 19979655 is about 4469.8607360856. The cubic root of 19979655 is about 271.3496890548.

The spelling of 19979655 in words is "nineteen million, nine hundred seventy-nine thousand, six hundred fifty-five".